.leaflet-zoom-box-control {
    font-size: 18px;
 }
.leaflet-zoom-box-control.active a {
    color: #FFF;
    background-color: #CCC;
    /*src: https://design.google.com/icons/#ic_center_focus_strong*/
    background-image: url();
}
.leaflet-zoom-box-crosshair {
    cursor: crosshair !important;
}
.leaflet-zoom-box-icon {
    background: transparent no-repeat center center;
    /*src: https://design.google.com/icons/#ic_crop_free*/
    background-image: url();
}
.leaflet-zoom-box-icon.leaflet-disabled{
    background-image: url();
}